Abstracts

Rationale: Mood disorders and epilepsy are suspected to have a bidirectional relationship. Epilepsy with comorbid mood disorders are associated in previous studies with impaired quality of life, increased adverse effects from antiseizure drugs (AEDs), drug resistance and poorer outcomes from epilepsy surgery. This study used data from the Providence Health and Services adult First Seizure Clinic (FSC) population to assess if commonly used screening questionnaire scores’ for depression and anxiety (PHQ9 and GAD7) can be used to predict occurrence of development of epilepsy as defined by the International League Against Epilepsy (ILAE) or a second seizure after a first unprovoked seizure. Methods: Data was abstracted from March 2016 and October 2018 excluding those declining consent, younger than 18 years old, declined, who had less than 3 months follow-up data, an index event (defined as first known seizure) which was provoked or non-epileptic at time of index event. Patients’ baseline PHQ9 and GAD7 screening scores at the time of the index event were recorded. A cut-off for positive screening questionnaire scores were established based on previous literature (PHQ9 ≥10 and GAD7 ≥9). Outcomes of interest were a diagnosis of epilepsy at any time during patient follow-up or occurrence of a second seizure following the FSC appointment. Descriptive analyses comparing those with and without symptoms were performed using Fisher’s Exact test and Mann-Whitney U tests, as appropriate l Multivariate logistic regression was used to analyze if a positive screening questionnaire could predict the odds of having a 2nd seizure or odds of being diagnosed with epilepsy controlling for age, insurance and marital status. Results: Seventy patients met inclusion criteria with a median follow-up time of 422.5 days [IQR(Interquartile range)=177-701]. Of the 65 eligible patients with baseline PHQ9 scores, 25.1% (n=14) screened positive for depression symptoms and of the 43 eligible patients with baseline GAD7 scores, 18.6% (n=8) screened positive for anxiety symptoms. Patients with PHQ9≥10 were more likely to be younger (28.0vs 42.0 p=0.008), single (85.7% vs 51.0%, p=0.03), and less likely to have private insurance (35.7% vs. 70.6%, p=0.037). Patients with GAD≥9 were also more likely to be younger (26.5 vs 42.0 p=0.024) and less likely to have private insurance (25.0% vs. 71.4%, p=0.027). Neither the PHQ9 (AOR=0.395, p=0.209) nor the GAD7 (AOR=0.301, p=0.284) scores were significantly related to an increased odds of having a second seizure. Similarly, PHQ9 (AOR=0.355, p=0.168) and GAD7 (AOR=0.167, p=0.125) scores were also not significantly related to an increased odds of an epilepsy diagnosis during follow-up. Conclusions: Consistent with previous literature, patients seen in the FSC had a higher percentage of positive depression screens than would be seen in the general population, which is approximately 8%, but were not more likely to have anxiety. However, those with depressive or anxious symptoms at the time of their first seizure were not more likely to develop epilepsy or have a recurrent seizure within a limited follow up interval. Future analyses will examine the relationship between mood score severity and time to epilepsy and second seizure, as well as the impact of AEDs and psychiatric medications, over a longer follow up interval. Funding: No funding